The present invention relates in general to two-state modulation and more particularly concerns a two-state modulation system embodying the principles of but representing an improvement over that disclosed in Bose U.S. Pat. No. 3,294,981 entitled SIGNAL TRANSLATION granted Dec. 27, 1966. The present invention is characterized by exceptionally good current control under all transient and steady state conditions of line and load, current limiting, a high degree of line and load regulation with stability and bandwidth, ability for parallelling with other like systems with proportional current sharing and great flexibility with respect to output circuits.
The basic two-state modulation system invented by Bose is characterized by high efficiency, ability to amplify faithfully in amplification circuits, exercise good control in feedback control systems and regulate voltage levels. The basic Bose system may include a power switch that energizes a low pass filter and is in a closed loop characterized by hysteresis that controls the instants of power switching so as to maintain the output of the low pass filter in conformity with a predetermined input, such as a reference voltage in the case of a voltage regulator, or a low level signal to be amplified in the case of an amplifier. A distinguishing feature of the Bose two-state modulator system is that a feedback signal from the output of the power switch ahead of the low pass filter initiates switching. This distinguishing feature is responsible for many of the advantages associated with two-state modulation.
It is an important object of this invention to retain the advantages associated with two-state modulation and provide additional advantages.
It is an important object of the invention to provide improved current control in a load under a wide variety of transient and steady state conditions of line and load.
It is another object of the invention to achieve one or more of the preceding objects while providing current limiting.
It is a further object of the invention to provide one or more of the preceding objects while highly regulating line and load parameters with good stability and over a wide bandwidth.
It is another object of the invention to achieve one or more of the preceding objects with a system suitable for parallelling with like systems to achieve proportional current sharing.
It is still another object of the invention to achieve one or more of the preceding objects with a flexible system applicable to a wide variety of output requirements.
Numerous other features, objects and advantages of the invention will become apparent from the following specification when ready in connection with the accompanying drawing in which: